| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.0 006/148] x86/mce: Fix MCE severity messages | Date | Wed, 3 Jun 2015 21:07:56 +0900 |
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4.0-stable review patch. If anyone has any objections, please let me know.
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From: Borislav Petkov <bp@suse.de>
commit 17fea54bf0ab34fa09a06bbde2f58ed7bbdf9299 upstream.
Derek noticed that a critical MCE gets reported with the wrong error type description:
[Hardware Error]: CPU 34: Machine Check Exception: 5 Bank 9: f200003f000100b0 [Hardware Error]: RIP !INEXACT! 10:<ffffffff812e14c1> {intel_idle+0xb1/0x170} [Hardware Error]: TSC 49587b8e321cb [Hardware Error]: PROCESSOR 0:306e4 TIME 1431561296 SOCKET 1 APIC 29 [Hardware Error]: Some CPUs didn't answer in synchronization [Hardware Error]: Machine check: Invalid ^^^^^^^
The last line with 'Invalid' should have printed the high level MCE error type description we get from mce_severity, i.e. something like:
[Hardware Error]: Machine check: Action required: data load error in a user process
this happens due to the fact that mce_no_way_out() iterates over all MCA banks and possibly overwrites the @msg argument which is used in the panic printing later.
Change behavior to take the message of only and the (last) critical MCE it detects.
Reported-by: Derek <denc716@gmail.com> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Link: http://lkml.kernel.org/r/1431936437-25286-3-git-send-email-bp@alien8.de Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- arch/x86/kernel/cpu/mcheck/mce.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-)
--- a/arch/x86/kernel/cpu/mcheck/mce.c +++ b/arch/x86/kernel/cpu/mcheck/mce.c @@ -705,6 +705,7 @@ static int mce_no_way_out(struct mce *m, struct pt_regs *regs) { int i, ret = 0; + char *tmp; for (i = 0; i < mca_cfg.banks; i++) { m->status = mce_rdmsrl(MSR_IA32_MCx_STATUS(i)); @@ -713,9 +714,11 @@ static int mce_no_way_out(struct mce *m, if (quirk_no_way_out) quirk_no_way_out(i, m, regs); } - if (mce_severity(m, mca_cfg.tolerant, msg, true) >= - MCE_PANIC_SEVERITY) + + if (mce_severity(m, mca_cfg.tolerant, &tmp, true) >= MCE_PANIC_SEVERITY) { + *msg = tmp; ret = 1; + } } return ret; }
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